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Data source: VAERS (Vaccine Adverse Event Reporting System)

Data through 2026 · Updated quarterly

Built by TheDataProject.ai · © 2026 VaccineWatch

Important: VAERS accepts reports of adverse events following vaccination. For any given report, there is no certainty that the reported event was caused by the vaccine. Reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable. Most reports to VAERS are voluntary, which means they are subject to biases. This data cannot be used to determine if vaccines cause or contribute to adverse events.

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Important: VAERS reports alone cannot determine if a vaccine caused an adverse event. Reports may contain incomplete, inaccurate, or unverified information. Correlation does not equal causation.

  1. Home
  2. Vaccine Side Effects
  3. Polio Vaccine
5 min read
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Polio Vaccine Side Effects

The polio vaccine is one of the greatest public health achievements in history, virtually eliminating polio in the developed world. VAERS tracks adverse events for both the current inactivated vaccine (IPV) and the historical oral vaccine (OPV).

71,449
Total Reports
2,511
Deaths Reported
7,798
Hospitalizations
2
Vaccine Types

Most Reported Side Effects

#1Pyrexia
10,468
#2Injection site erythema
10,096
#3Erythema
5,283
#4Injection site swelling
5,190
#5Vomiting
4,020
#6Injection site warmth
3,823
#7Injection site oedema
3,736
#8Rash
3,397
#9Urticaria
3,312
#10Convulsion
3,005
#11Injection site pain
2,744
#12Injection site induration
2,514

IPV vs OPV

  • IPV (Inactivated Polio Vaccine / IPOL): Current standard in the U.S. — given by injection, contains killed virus. Cannot cause polio.
  • OPV (Oral Polio Vaccine): Historical — given by mouth, contains weakened live virus. No longer used in the U.S. since 2000 due to extremely rare cases of vaccine-derived polio.

Important context: most IPV VAERS reports are from combination vaccines (like DTaP-IPV) where the polio component is given alongside other antigens. Side effects may be from the combination rather than the polio component specifically.

Expected Side Effects (IPV)

Common:

  • Soreness and redness at injection site
  • Low-grade fever
  • Fussiness (in infants)

IPV is considered one of the safest vaccines. Serious adverse events directly attributable to IPV are extremely rare.

Historical Context: VAPP

The oral polio vaccine (OPV) carried a very small risk of vaccine-associated paralytic polio (VAPP) — about 1 case per 2.4 million doses. This is why the U.S. switched exclusively to IPV in 2000. OPV is still used in some countries for its ability to provide intestinal immunity and stop wild poliovirus transmission.

IPV is given as a multi-dose series in childhood. See when each dose is due on the CDC vaccine schedule and our 2026 vaccine schedule analysis.

Explore This Data

IPV Detail →
Full VAERS profile
Pediatric Analysis →
Childhood vaccine data
All Side Effects →
Complete guide

2026 Safety Monitoring Update

As of mid-2026, the polio vaccine continues to be monitored through VAERS and complementary surveillance systems including the Vaccine Safety Datalink (VSD) and the Clinical Immunization Safety Assessment (CISA) project. No new safety signals have been identified in recent data that would change the established safety profile of this vaccine.

The HHS administration's announced development of AI-powered VAERS analysis tools may provide additional insights into polio vaccine adverse event patterns. These tools aim to detect subtle signals that traditional statistical methods might miss, though their implementation timeline and methodology remain under development.

It's worth noting that VAERS reporting for routine vaccines like polio has remained stable through the post-pandemic period. While COVID-19 vaccine reports surged and then declined, reporting patterns for established childhood and adult vaccines have been remarkably consistent, suggesting that the VAERS system continues to function as designed for ongoing safety surveillance.

Understanding VAERS Data for polio

When interpreting VAERS data for polio vaccines, several key principles apply:

  • Reports ≠ Causation: A VAERS report means an event occurred after vaccination. It does not establish that the vaccine caused the event. Many reported symptoms are common health occurrences that would happen regardless of vaccination.
  • No denominator: VAERS does not track the number of doses administered. Without knowing how many people received the vaccine, raw report counts cannot be used to calculate risk rates or compare safety across vaccines.
  • Co-administration: Many vaccines are given at the same visit. When a VAERS report lists multiple vaccines, it's impossible to determine which vaccine (if any) was responsible for the reported adverse event.
  • Reporting variability: Healthcare provider awareness, media attention, and public concern all influence how many reports are filed. Changes in report volume may reflect changes in reporting behavior rather than changes in actual safety.

How to Use This Data Responsibly

VAERS data is most useful as a starting point for conversation with your healthcare provider, not as a basis for medical decisions. If you're concerned about polio vaccine side effects:

  • Discuss your specific risk factors with your doctor or pharmacist
  • Ask about the relative risks of the disease the vaccine prevents vs. the vaccine itself
  • Consider your age, health status, and any previous vaccine reactions
  • Remember that clinical trials and post-market studies provide much stronger safety evidence than VAERS alone

For the most up-to-date safety information, consult the CDC's vaccine information pages or speak with a qualified healthcare professional.

More Resources

When Do Side Effects Start?
73% occur within 3 days of vaccination
Serious vs Non-Serious Outcomes
The full severity spectrum in VAERS
Report an Adverse Event
How to file a VAERS report
Our Methodology
How we process VAERS data

2026 Safety Monitoring Update

As of mid-2026, the polio vaccine continues to be monitored through VAERS and complementary surveillance systems including the Vaccine Safety Datalink (VSD) and the Clinical Immunization Safety Assessment (CISA) project. No new safety signals have been identified in recent data that would change the established safety profile of this vaccine.

The HHS administration's announced development of AI-powered VAERS analysis tools may provide additional insights into polio vaccine adverse event patterns. These tools aim to detect subtle signals that traditional statistical methods might miss, though their implementation timeline and methodology remain under development.

It's worth noting that VAERS reporting for routine vaccines like polio has remained stable through the post-pandemic period. While COVID-19 vaccine reports surged and then declined, reporting patterns for established childhood and adult vaccines have been remarkably consistent, suggesting that the VAERS system continues to function as designed for ongoing safety surveillance.

Understanding VAERS Data for polio

When interpreting VAERS data for polio vaccines, several key principles apply:

  • Reports ≠ Causation: A VAERS report means an event occurred after vaccination. It does not establish that the vaccine caused the event. Many reported symptoms are common health occurrences that would happen regardless of vaccination.
  • No denominator: VAERS does not track the number of doses administered. Without knowing how many people received the vaccine, raw report counts cannot be used to calculate risk rates or compare safety across vaccines.
  • Co-administration: Many vaccines are given at the same visit. When a VAERS report lists multiple vaccines, it's impossible to determine which vaccine (if any) was responsible for the reported adverse event.
  • Reporting variability: Healthcare provider awareness, media attention, and public concern all influence how many reports are filed. Changes in report volume may reflect changes in reporting behavior rather than changes in actual safety.

How to Use This Data Responsibly

VAERS data is most useful as a starting point for conversation with your healthcare provider, not as a basis for medical decisions. If you're concerned about polio vaccine side effects:

  • Discuss your specific risk factors with your doctor or pharmacist
  • Ask about the relative risks of the disease the vaccine prevents vs. the vaccine itself
  • Consider your age, health status, and any previous vaccine reactions
  • Remember that clinical trials and post-market studies provide much stronger safety evidence than VAERS alone

For the most up-to-date safety information, consult the CDC's vaccine information pages or speak with a qualified healthcare professional.

More Resources

When Do Side Effects Start?
73% occur within 3 days of vaccination
Serious vs Non-Serious Outcomes
The full severity spectrum in VAERS
Report an Adverse Event
How to file a VAERS report
Our Methodology
How we process VAERS data

More Side Effect Guides

DTaP Side Effects
Given at same visits as IPV
Rotavirus Side Effects
Another infant vaccine
MMR Side Effects
Measles, mumps, rubella